You Don’t Know the Half of It: Temperature Adjustments and the Australian Bureau of Meteorology

For the true believer, it is too awful to even consider that the Australian Bureau of Meteorology could be exaggerating global warming by adjusting figures. This doesn’t mean though, that it’s not true.

Look carefully and you will see Pinocchio.

In fact, under Prime Minister Tony Abbott, a panel of eminent statisticians was formed to investigate these claims detailed in The Australian newspaper in August and September 2014. The panel did acknowledge in its first report that the Bureau homogenized the temperature data: that it adjusted figures. The same report also concluded that it was unclear whether these adjustments resulted in an overall increase or decrease in the warming trend. No conclusions could be drawn because the panel did not work through a single example of homogenization, not even for Rutherglen. Rutherglen is of course in north eastern Victoria, an agricultural research station with a continuous minimum temperature record unaffected by equipment changes or documented site-moves, but where the Bureau nevertheless adjusted the temperatures. This had the effect of turning a temperature time series without a statistically significant trend, into global warming of almost 2 degrees per Century.

According to media reports last week, a thorough investigation of the Bureau’s methodology was prevented because of intervention by Environment Minister Greg Hunt. He apparently argued in Cabinet that the credibility of the institution was paramount. That it is important the public have trust in the Bureau’s data and forecasts, so the public know to heed warning of bushfires and cyclones.

This is the type of plea repeatedly made by the Catholic Church hierarchy to prevent the truth about paedophilia, lest the congregation lose faith in the church.

Contrast this approach with that by poet and playwright Henrik Ibsen who went so far as to suggest ‘the minority is always right’ in an attempt to have his audience examine the realities of 18th Century morality. Specifically, Ibsen wanted us to consider that sometimes the individual who stands alone is making a valid point which is difficult to accept because every culture has its received wisdoms: those beliefs that cannot be questioned, until they are proven in time to have been wrong. British biologist, and contemporary of Charles Darwin, Thomas Huxley was trying to make a similar point when he wrote, “I am too much of a skeptic to deny the possibility of anything.”

Mr Hunt defends the Bureau because they have a critical role to play in providing the Australian community with reliable weather forecasts. This is indeed one of their core responsibilities. They would, however, be better able to perform this function, if they used proper techniques for quality control of temperature data, and the best available techniques for forecasting rainfall [1]. Of concern, there has been no improvement in their seasonal rainfall forecasts for two decades because they use general circulation models [2]. These are primarily tools for demonstrating global warming, with dubious, if any skill, at actually forecasting weather or climate.

Consider for example, the Millennium drought and the flooding rains that followed in 2010. Back in 2007, and 2008, David Jones, then and still the Manager of Climate Monitoring and Prediction at the Bureau of Meteorology, wrote that climate change was so rampant in Australia, “We don’t need meteorological data to see it” [3], and that the drought, caused by climate change, was a sign of the “hot and dry future” that we all collectively faced [4]. Then the drought broke, as usual in Australia, with flooding rains. But the Bureau was incapable of forecasting an exceptionally wet summer, because such an event was contrary to how senior management at the Bureau perceived our climate future. So, despite warning signs evident in sea surface temperature patterns across the Pacific through 2010, Brisbane’s Wivenhoe dam, a dam originally built for flood mitigation, was allowed to fill through the spring of 2010, and kept full in advance of the torrential rains in January 2011. The resulting catastrophic flooding of Brisbane is now recognized as a “dam release flood”, and the subject of a class action lawsuit by Brisbane residents against the Queensland government.

Indeed despite an increasing investment in super computers, there is ample evidence that ideology is trumping rational decision making at the Bureau on key issues that really matter, like the prediction of drought and flood cycles. Because a majority of journalists and politicians desperately want to believe that the Bureau knows best, they turn away from the truth, and ignore the facts.

News Ltd journalist Anthony Sharwood got it completely wrong in his weekend article defending the Bureau’s homogenization of the temperature record [5]. I tried to explain to him on the phone last Thursday, how the Bureau don’t actually do what they say when they homogenize temperature time series for places like Rutherglen. Mr Sharwood kept coming back to the issue of ‘motivations’. He kept asking me why on earth the Bureau would want to mislead the Australian public. I should have kept with the methodology, but I suggested he read what David Jones had to say in the Climategate emails. Instead of considering the content of the emails that I mentioned, however, Sharwood wrote in his article that, “Climategate was blown out of proportion”, and “independent investigations cleared the researchers of any form of wrongdoing”.

Nevertheless, the content of the Climategate emails includes quite a lot about homogenization, and the scientists’ motivations. For example, there is an email thread in which Phil Jones (University of East Anglia) and Tom Wigley (University of Adelaide) discuss the need to get rid of a blip in global temperatures around 1940-1944. Specifically Wigley suggested they reduce ocean temperatures by an arbitrary 0.15 degree Celsius. These are exactly the types of arbitrary adjustments made throughout the historical temperature record for Australia: adjustments made independently of any of the purported acceptable reasons for making adjustments, including site moves, and equipment changes.

Sharwood incorrectly wrote in his article that: “Most weather stations have moved to cooler areas (i.e. areas away from the urban hear island effect). So if scientists are trying to make the data reflect warmer temperatures, they’re even dumber than the sceptics think.” In fact, many (not most) weather stations have moved from post offices to airports, which have hotter, not cooler, day time temperatures. Furthermore, the urban heat island creeps into the official temperature record for Australia, not because of site moves, but because the temperature record at places like Cape Otway lighthouse is adjusted to make it similar to the record in built-up areas like Melbourne, which are clearly affected by the urban heat island [6].

I know this sounds absurd. It is absurd, and it is also true. Indeed, a core problem with the methodology that the Bureau uses is its reliance on “comparative sites” to make adjustments to data at other places. I detail the Cape Otway lighthouse example in a recent paper published in the journal Atmospheric Research, volume 166, page 145 [6].

It is so obvious that there is an urgent need for a proper, thorough and independent review of operations at the Bureau. But it would appear our politicians and many mainstream media are set against the idea. Evidently they are too conventional in their thinking to consider that such an important Australian institution could now be ruled by ideology.

5. Sharwood, A. 2015. Why are they messing with the data? http://www.news.com.au/technology/environment/the-cyclone-tracy-of-ideological-battles-does-the-weather-bureau-tweak-data-or-is-our-government-paranoid/story-fnjwvztl-1227545670243?sv=a58a1574c4a196289acf208f11fc2d2b

Reader Interactions

Comments

One could appreciate the legendary Sisyphus in these matters.Quite extraordinary that so-called journalists will not consider these allegations seriously- then again it takes commitment and open-mindedness.Good stuff Jen.

It was quite obvious when Tony Jones interviewed Greg Hunt on Lateline last week that he was ridiculing the idea that the Abbott government would even consider investigating such a revered organisation as BOM (as revered as the ABC no doubt). Had Greg Hunt not been able to emphatically state he had “nipped the idea in the bud” he would have been ridiculed further by Tony Jones. Of course what should have happened is that Tony Jones should have delved further into why such an investigation was being considered and what might have warranted it, and why it was cut short. But this is what we are faced with – an ABC (who we are supposed to trust!) with a completely one eyed approach to the subject. And for the government, a politically risky path to follow. The only thing that can be done is for people like you, Jennifer, to keep banging the door.

“Consider for example, the Millennium drought and the flooding rains that followed in 2010. Back in 2007, and 2008, David Jones, then and still the Manager of Climate Monitoring and Prediction at the Bureau of Meteorology, wrote that climate change was so rampant in Australia, “We don’t need meteorological data to see it” [3], and that the drought, caused by climate change, was a sign of the “hot and dry future” that we all collectively faced [4]. Then the drought broke, as usual in Australia, with flooding rains. But the Bureau was incapable of forecasting an exceptionally wet summer, because such an event was contrary to how senior management at the Bureau perceived our climate future.”

These people are more like religious extremists and certainly don’t sound like serious scientists. According to the HAD 4 data we’ve only had a slight 0.8 C of warming over the last 165 years and this comes after the end of a minor ice age. What would you expect?

“He apparently argued in Cabinet that the credibility of the institution was paramount.”

From what I can see it is now widely accepted that the temperature data is fraudulently upjusted by “troughers” (those with their snouts so deep in the trough of public money they no longer can, or even want, to see the truth).

I am not convinced – but the temperature record published by J Marohasy for Rutherglen has sure got me very worried – because it certainly looks as though the official historical series has been incorrectly adjusted by the BOM. Obviously there is pressure on scientists in Government and academia to pursue research that supports the prevailing “consensus” – and yet, historically, science has often advanced because an individual or group has differed with the prevailing view. We, as a global society, are spending not billions but trillions of dollars pursuing the prevailing view, when evidence appears to be mounting that it may be wrong – at least in quantum. Therefore we really do need an independent review, akin to a Royal Commission, to confirm that the huge expenditure is soundly based and effective. There are many very serious problems facing humanity that could be solved if we could redirect just a fraction of this expenditure to their solution. Do we have to wait for the onset of the next inevitable ice age before we, as a global society, demand an independent review of the current “consensus” and whether or not our public institutions are serving us well?

When considerably more than half of the temperature data that is compiled by the world’s gate keepers is reconstructed rather than raw and we hear from these same gate keepers how it is a “travesty” the world is not warming sufficiently to suit their agenda, and this agenda includes extracting mind-numbing amounts of taxpayer funds to basically unaccountable people, it is inconceivable that these gate keepers are not regularly audited along similar lines to other people or entities who also have a vested interest in fooling governments and taxpayers.

Neville, not only did the BOM use the Millennium Drought as the proof of the coming climate armageddon, and then quickly drop it as the drought ended, but the BOM has effectively removed the well documented Federation Drought (1896-1902) from the record and from discussion. Check how many temperature records start in 1905 or so.

BOM have done this to be able to adjust down early last century temperatures which is an integral part of the procession of “hottest xxx ever” claims, and also to prevent embarrassment at the true temperatures and rainfalls experienced during the Federation Drought. Without this early downward adjustment, the current ‘global warming’ temperature increase over the 20th century doesnt exist.

The reasons given for excluding the earlier drought data are many and varied, the strongest being ‘unreliable measurement’. But long, pristine raw temperature records through this period do exist, free from site moves, instrumentation changes etc. And I’m sure BOM know these records exist.

Perhaps its time these crucial long data are brought series back out into the open, and into discussion? It is central to the BOM homogenisation fiasco.

Excellent job, Jennifer. And you came back with responses in the comments section [The Australian Online Opinion] when the usual suspects moved in. I have not noticed many people having the guts to do that.
Eric Lobbecke’s cartoon is going to stick in a lot of people’s minds 🙂

Thank you for your article in today’s Australian. Maybe Dorothea Mackeller showed in her 1908 poem that she understood Australia’s Climate better than the two Jones boys of today.
I wish you well with your research into droughts and rainfall and how to predict the same. This would be worth far more to our economy than fiddling with past temperature records. I would also like to see more work on disaster preparedness and recovery for droughts, floods, fires, and cyclones. We are going to have these events irrespective of co2 levels in the atmosphere.or the results of the coming Paris junket.

Blogger Tony Heller showed how NOAA adjustments had turned a US State’s cooling trend into a warming trend. I sent the State Climatologist of that state an email asking if he had any comments. His reply to me:

“1. NOAA’s temperature adjustments are not perfect.
2. They may produce a positive temperature trend bias.
3. They are not fraudulent.”

Jennifer Marohasy is carrying out splendid work, revealing how great is the manipulation of the climate statistics by the BOM in pursuit of support of the CAGW/Global Warming cause. CAGW is now an officially registered religion and even receives government funding and protection from criticism. When the only warming visible is the result of manipulation of data, there is a serious public trust problem that will pursue the BOM doggedly. The BOM has lost its credibility and its CO2/CAGW forecasts are so poor that it has lost public trust completely.

The temperature data is fraudulently upjusted by the BOM and Jennifer Marohasy is revealing the extent of this fraud quite diligently.

President Obama has been urged to commence criminal prosecutions against sceptics.

I’ve been waiting for a proper judicial enquiry into the scientific basis of AGW, including qualification of uncertainty and the vagaries of climate model predictions for years.

That would involve scientists giving testimony under oath and being cross-examined.

In Australia, I was hoping for a Royal Commission – scratch that under Minister Hunt. If he can’t even contemplate review of BoM temperature adjustments which conveniently make the pause disappear, just as it was getting awkward for true believers, then doing a due diligence of a $4B per year taxpayer handout to green energy spivs, won’t fly.

However, a criminal investigation leading to a trial in the US might be just as interesting!

Healthy human temperature ranges from 97.8C to 99.0C and traditional thermometers invented in about 1714, and used since in medicine to measure the healthy human temperature range, show the historical healthy human temperature range is as valid today as when the thermometer was first used in medicine.

If temperature homogenisations are necessary in climate and meteorology because of ‘issues’ with scientific thermometers, equipment, and location – I’d have thought there would be a Lancet article by now describing why similar adjustments are now required to address the same issues in historical medical data?

“In fact, many locations along the UK, US and Australian coasts will experience their highest tides for tens of years around September 29 or 30. Coastal roads in Miami, for instance, have already been closed in anticipation of exceptional tides.

“These high tides may bring water levels uncomfortably close to the tops of harbour walks and flood defences, emphasising the threat of rising sea levels.”

In fact, rather than record high tides [they were at least a foot below average king tide height] the low tides were so low that a friend’s pontoon actually broke away from its mounting. It had never experienced such low tides ever before and there are many anecdotal stories of boats in marinas going aground that have never done so before.

Gavin Schmidt claims that co2 is a non-condensing greenhouse gas, and because it doesn’t condense that co2 “is the key factor in sustaining Earth’s greenhouse effect”.
“Carbon dioxide is responsible for 80 percent of the radiative forcing that sustains the Earth’s temperature“, he says.

Bone of contention, carbon dioxide manages to condense out of the Mars atmosphere.
I’ve watched it happen in real time, as the ice caps melt with the seasons.
Something else worth mentioning. There are no storm clouds. Just sand blown about. Sometimes huge planet obscuring sand storms, but they’re only visible due to the sand.

Co2 is transparent to all visible light. Co2 obscures infrared. So if there are big billowing clouds of co2 snowing out to replenish the Martian ice caps as the seasons turn, which there absolutely has to be, then they are invisible clouds precipitating, condensing invisible co2 ice directly onto the winter ice cap.

Given the upper atmosphere of Earth is cold, 50,000 feet up, why wouldn’t the Earth have invisible co2 clouds condensing dry ice here, falling but not reaching the surface?

Oh how I wish the weather was as predictable as the actions of G Hunt, Bom, ABC, etc.etc,. It would make the unenviable task of producing the world’s most important commodity, FOOD, a bloody lot easier. Am lookind forward to the day I can click on the ‘Marohasy/Abbot Forecast’ and plan with a little more confidence. ‘Pin-the tail-on-the-Donkey’ is more reliable than the Global circulation Models worshipped by BOM.

Schmidt is a wee bit deceptive with his non-condensing distraction. CO2 reacts out. Co2 reacts with water, with plants and other biological systems, with stone, with soil, with microbes and so much more.
Condensing is irrelevant.

I am not a scientist, just a layperson who has been looking at the skeptical side of climate change. What I’m reading seems to make more sense to me than what is being said on the alarmist side. I have a couple of questions that I hope someone may be able to answer on this site. First, I found a site called “The Global Warming Petition Project” which states it has over 30,000 signatures of climate skeptics. Is anyone familiar with this site? Is it legitimate? Second, I’ve been reading that CO2 is not a pollutant and is beneficial for vegetation–the more the better. However, with all the forests and farmland being lost to development, is there a point where the plants are not able to take it all in? Does the planet just mitigate it naturally then. I’m sure these questions may seem to be very Climate Skeptic 101 to you all, but if someone could explain in layman’s terms, I’d appreciate it.

James,
I am not speaking about rain. I am suggesting that a photon of a particular wavelength does not care if it is absorbed by CO2 or H2O.
Yes, I agree: GWP is a mess. More like a made up scary term.
The cliamte kooks seem to think that atmospheric dynamics were created with the industrial age.

A few years ago, I was listening to a BOM spokesperson talking about high temperatures and he used very carefully chosen words “This is the hottest day in Melbourne since OFFICIAL records began” – It got me thinking that there was something VERY HOT prior to the beginning of official records that he knew about.

After some searching, I found it. A day in 1851, known as black Thursday (look it up in Wikipedia) where the temperature in Melbourne was measured at 47 deg C at 11am (even higher noted in other sources) and bushfires began which burned around 25% of Victoria’s land area as well as much of southern NSW and SA. The Tasmanian newspapers said the sky went as dark as night in Tasmania, the birds went quiet and many went to the churches to pray.

All the more reason to deal with atmospherics in a more realistic manner. Ambient temperature doesn’t care about photons, how many of what type hit here or there. Temperature only cares how fast the molecules are colliding.
H2O and CO2 both take a bunch of hits to get their lard butt moving. Because they’re slow. But they make up for it by taking a good punch.

Martin Clark–Thank you for pointing me in the right direction. I’m trying to become as informed as possible about what is actually happening with our climate, especially when talking with friends and relatives who are in a panic about “Catastrophic Global Warming.”

There are several blog sites that promote the “science” of climate change denial..or at least USED to promote absolute denial that ANYTHING was happening or that CO2. was a main player in the ‘greenhouse effect” that brought about climate change wrought by human activity…they USED to be like that , but now, through a series of cunning segues, they have morphed into a kind of apologist for the theory that ; “Ok, ok..there IS climate change, but hey!..climate is always changing…” and are turning their hand toward blaming the Bureau of Meteorology for fudging the figures to make it APPEAR that the temp’s are increasing.

The Jennifer Marohasy blog site holds to this proposition, with article after article, post after post holding to such conspiracy supporting the author with varying degrees of sickening, fawning obsequiousness that would do the most groveling eunuch from medieval history proud…and by jeesus..there were plenty of them!

Of course, I protested the thesis and of course I was moderated out..I protested , not with the mathematics of science, I do not have that training, but with an example of common sense..it went like this :

Down the front of my property, there are three underground tanks…within pointing distance, there are at least half a dozen more on my and other properties..all dug around the same time..(ca. 1900) all around the same volume (10’ x 10’ x 10’ ), all dug by hand…I’ll repeat that for those who have at any time in their life, dug a hole of any depth in dry hard soil…ALL dug by hand. Added to that snippet of info’ is the geological knowledge that the mallee soil has a layer of calcrete from several inches to several feet thick…that will make the reverberating steel of a crowbar ring and hum like a full brass section of the Berliner Philharmonic !…So my common sense thesis rests on the fact..mark that ; FACT ..that to commence to dig a conglomerate of underground tanks through the above described soil, to collect run-off rain-water would , unless one was an absolute imbecile, necessitate a degree of “figgerin’ “..:

a) Is there enough run-off in this position?
b) Is there consistent run-off of rain ?
c) Is my back up to the job?

Such questions would, I imagine, appeal to the rational mind. Now, given that those aforementioned tanks, still in situ, still serviced by the swales to assist water run-off, WERE dug, DID cut through the calcrete layer and are NOW obvious by their dryness..AND were claimed by the previous owner (of the original pioneer family who dug the tanks) to not have been filled for at least the last forty year BEFORE we purchased the property…then by applying the most obtuse reasoning by the most simplistic mind , one would have to presume that something has changed…; not the location, not the intention, not the slope of the landscape…but only the rainfall.

And , of course, I was moderated out…to, I presume the glee of those arse-lickers who support the thesis of the blog owner. Now there is a worse accusation than mere bloody-mindedness in that blocking of my post, given that it proposed questions that hinge on the common knowledge and experience of not just those local pioneers who dug those tanks, but on the accrued knowledge of collected humanity..the sense of calculated locating , tracing, observing and judging with the nous of the human ingenuity and eye and capability coupled with determination and experience to be able to harness the bounty of nature to benefit the labour of humanity…in short ; cunning of eye meets skill of hand…a practice, I’ll warrant, that has served humanity through may a dire situation over many millennia.

But I was blocked..and this tells me that those people, be they excellently educated, highly placed in either academia or bureaucracy..are precariously balanced on the tipping-point of absolute, mind-numbing imbecility. Because by promoting educated theory to the detriment of work-experience practicality, is to deny night follows day simply because one is wearing a blindfold. Those blogs that promote BOM. Conspiracy coupled with blind to the bleedin’ obvious practicalities of reality reflect a mind-set that has truly been educated to imbecility.

Sadly, I doubt there is anything one can do , save placing them in a cushioned corner and give them a “Chuppa-Chup” to suck on!

JC I know I’m wasting my time, but I’ll try again. Here’s the BOM rainfall graph for South OZ since 1900. I’ve set it for average rainfall and you’ll note the biggggg 17 drought from about 1922 to 1939. Now the IPCC tells us that the impact from co2 should be seen after 1950, but for S OZ the last 65 years has been wetter than the period 1900 to 1950.
I know this is a problem for you but that’s the data you have to deal with. Sorry it disproves your rant. But the long term data does show that S OZ has been cooling for the last 7,000 years and rainfall has been reducing as well. See Calvo et al study using Alkenone proxies off SA coast.

Just to observe how some of these religious fanatics behave when they’re confronted with satellite data showing no warming for over 18 years. You have to watch this video to understand how loopy these fools are. BTW a good job by Senator Ted Cruz.

Down the front of my property, there are three underground tanks…within pointing distance, there are at least half a dozen more on my and other properties..all dug around the same time..(ca. 1900) all around the same volume (10’ x 10’ x 10’ ), all dug by hand…I’ll repeat that for those who have at any time in their life, dug a hole of any depth in dry hard soil…ALL dug by hand. Added to that snippet of info’ is the geological knowledge that the mallee soil has a layer of calcrete from several inches to several feet thick…that will make the reverberating steel of a crowbar ring and hum like a full brass section of the Berliner Philharmonic !…

Three tanks within pointing distance says to me that one wasn’t collecting enough water to make a go of it. The two extra were wish casting for the rainy season. Sort of a rain dance.

Neville…as much as I would truly like to say in regards to your BOM. graph ; “Oh..that’s alright then..I fully accept your premise!”…I can’t..because, you see, while you are looking at a monitor screen and seeing “bounty”, I am looking out a window and seeing that the bounty has slipped away…and no figures on a page is worth a scrape of cocky-cack to a drying environment.

And as ..I.. have said before..here, any rain at or below 5mm. is not worth putting on a list of averages…as a matter of fact, I would now lift that amount to anywhere under 10mm. as the showers that would deliver that amount are so long in between drinks, and the ground so dry at any usable depth, there is “nothing in the bank” for growing plants to draw upon to make that small amount, which will evaporate in little more than one hour for a low amount and half a day for the higher amount giving little more than false hope in the most important time of the growing season.

So that “averages for SA.” , drawing as it must do , from the wettest areas of the state, have no meaning for what was once the medium to marginal farming districts of the state. and it is there that the effects of the totally erratic weather patterns are most felt…there on the front-line of the effects of climate change..or rather HERE, where I am sited. Your graph would be seen as a joke to most people in the area as they witness the shutting down of storage silos, shops and businesses that service the areas..An insult to the families who have invested generations into farming enterprises that now are at risk or have already folded, been broken up and moved away. Your ; “Nothing to see here folks” an insult to the many traumatised families who have seen fathers and brothers suffer the pangs of guilt at failing in a climate beyond their capacity to manage and feeling the blame for the loss of a multi generational farming enterprise that once gave high profit to their fathers/ grandfathers, now can barely sustain the mortgage on the high-cost tooling-up of machinery and cropping borrowings.

It is a ghastly joke and a foolish gesture to break into jocular song at what must be the makings of a funeral march..and with your clumsy gesture at rationalising such a decline, yours is just such a joke and the shifting of a decimal point or a minor percentage to “prove a point” is of negligible balm to a declining prospect.

JC I’ve got relatives in the grain business in the nth mallee and SW NSW and some of what you’ve said has some truth.
But Mildura in Vic has temps and rainfall records going back to 1889 and the record to 1946 for rainfall is 268mm year and since then is 291 mm a year. And the temp hasn’t increased over that time.

The grain industry is a hard game for sure but some farmers seem to manage, although it’s always a gamble. I’ve given you the correct data from the BOM for SA since 1900 and if you can’t accept it that’s your problem.
BTW the 12th century was a horror century for OZ droughts according to the recent Vance et al study and one drought lasted 39 years. And there were a number of droughts over the last 1,000 years that equalled our recent bad drought.
I’m afraid if you don’t like droughts and flooding rains you should move to another country. Don’t forget we’ve had the bad fed drought and 1940s droughts that both occurred when co2 couldn’t be a factor. That’s according to the IPCC. Also I’ve shown that SA had record below average rainfall from 1922 to 1939 well before the 1950 IPCC impact date.

In the 2010 BBC extended interview Phil Jones had this to say from point G.

G – There is a debate over whether the Medieval Warm Period (MWP) was global or not. If it were to be conclusively shown that it was a global phenomenon, would you accept that this would undermine the premise that mean surface atmospheric temperatures during the latter part of the 20th Century were unprecedented?

“There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia. For it to be global in extent the MWP would need to be seen clearly in more records from the tropical regions and the Southern Hemisphere. There are very few palaeoclimatic records for these latter two regions.

Of course, if the MWP was shown to be global in extent and as warm or warmer than today (based on an equivalent coverage over the NH and SH) then obviously the late-20th century warmth would not be unprecedented. On the other hand, if the MWP was global, but was less warm that today, then current warmth would be unprecedented.

We know from the instrumental temperature record that the two hemispheres do not always follow one another. We cannot, therefore, make the assumption that temperatures in the global average will be similar to those in the northern hemisphere.” End of point G.

So here’s my response, we have the PAGES 2K study and the Calvo et al study that both show a warmer Med WP in Antarctica and S OZ, plus there are studies from S America and NZ that support this as well. So using Jone’s concession we can say that there is nothing unprecedented or unusual about the slight 0.8 C of warming since 1850. And this slight warming comes at the end of a minor ice age. Big deal. BTW here’s the full Jones interview, well worth a read.

A comment above , from DaveR, about them removing the Federation Drought, comes after an owner of a Riverina station recently told me about the station records.
They stated that in the early 1890’s 60,000 sheep were shorn there annually, but in 1902 , only 6,000 were left to shear.
Someone at the BOM better find that book and adjust it. It is blasphemous.